The disclosures of Japanese Patent Applications Nos. 2000-257682 filed on Aug. 28, 2000 and 2000-257795 filed on Aug. 28, 2000, each including the specification, drawings and abstract are incorporated herein by reference in their entireties.
1. Field of the Invention
The invention relates to a head-protection airbag device mounted in vehicles.
2. Description of Related Art
This type of head-protection airbag devices includes a head-protection airbag device in which an airbag stored along a roof side rail has a gas-introducing path at its upper edge. A gas is supplied from a gas supplier into an inflation chamber through a gas distribution pipe provided within the gas-introducing path, whereby the airbag is inflated and deployed like a curtain along the sidewall of the vehicle compartment so as to protect a head of an occupant. Such a head-protection airbag device is described in, e.g., International Publication No. 98/22313 and Japanese Laid-Open Publication Nos. 11-301394 and 11-314555.
In the aforementioned conventional head-protection airbag device, gas outlets of the gas distribution pipe are oriented in the same direction with respect to the inflation chamber of the airbag. It is therefore impossible to deploy each portion of the airbag (e.g., the portions respectively corresponding to a door glass portion and a pillar garnish portion) in an optimal direction. Moreover, a reduction in the time for completion of deployment of the airbag has been required in such a head-protection airbag device. Thus, there is a need for an improved head-protection airbag device in these respects.
A head-protection airbag device according to a first aspect of the invention includes an airbag stored along a roof side rail and including a gas-introducing path at its upper edge. A gas is supplied from a gas supplier into an inflation chamber through a gas distribution pipe provided within the gas-introducing path, whereby the airbag is inflated and deployed like a curtain along a sidewall of a vehicle compartment so as to protect a head of an occupant. Gas outlets in the gas distribution pipe are opened in different directions depending on a region of the air bag.
According to the first aspect of the invention, the airbag is normally stored along the roof side rail in a folded state. Upon side impact, rollover or the like of a vehicle, the gas is supplied from the gas supplier through the gas distribution pipe into the inflation chamber of the airbag, whereby the airbag is inflated and deployed like a curtain along the sidewall of the vehicle compartment. At this time, with the gas supplied from the gas supplier, an inflatable portion of the airbag is inflated and deployed toward a head-protection inflation area that is located laterally to the head of the occupant. The gas outlets in the gas distribution pipe are opened in different directions depending on a region of the airbag. This enables each part of the airbag to be deployed in a desired direction, whereby the deployment direction can be optimized for each part of the airbag.
In the first aspect of the invention, the gas outlets may be opened in different directions according to a resistance of an interior member against deployment of the airbag. Accordingly, each gas outlet corresponding to a region that is subjected to a large resistance against deployment of the airbag may be opened toward that region in order to supply a large amount of gas thereto. On the other hand, each gas outlet corresponding to a region that is subjected to a small resistance against deployment of the airbag may be opened away from that region in order to supply a small amount of gas thereto. This enables approximately uniform deployment of the airbag, allowing a reduction in the deployment time of the airbag.
In the first aspect of the invention, the gas outlets may be opened in different directions in a region corresponding to a door glass portion and in a region corresponding to a pillar garnish portion. This enables the gas to be accurately supplied to the respective regions of the airbag corresponding to the door glass portion and the pillar garnish portion, allowing for improvement in inflation/deployment capability of the airbag.
In the aforementioned aspect of the invention, the gas outlet in the region corresponding to the door glass portion may be opened in a direction that crosses a door glass plane, and the gas outlet in the region corresponding to the pillar garnish portion may be opened in a direction over a pillar garnish. Accordingly, the airbag can be deployed along, and in contact with, the door glass plane in the region corresponding to the door glass portion. This enables the airbag to be accurately interposed between the door glass portion and the head of the occupant even if there is only a small space therebetween. Moreover, in the region corresponding to the pillar garnish portion, the airbag can be deployed in the direction over the pillar garnish. This can prevent the airbag from being hooked at the pillar garnish.
A head-protection airbag device according to a second aspect of the invention includes an airbag stored along a roof side rail and including a gas-introducing path at its upper edge. A gas is supplied from a gas supplier into a plurality of inflation chambers of the airbag through a plurality of gas outlets of a gas distribution pipe provided within the gas-introducing path, whereby the airbag is inflated and deployed like a curtain along a sidewall of a vehicle compartment so as to protect a head of a seated occupant. The gas outlets of the gas distribution pipe are disposed corresponding only to predetermined inflation chambers.
A head-protection airbag device according to a third aspect of the invention includes an airbag stored along a roof side rail and including a gas-introducing path at its upper edge. A gas is supplied from a gas supplier into a plurality of inflation chambers of the airbag through the gas-introducing path, whereby the airbag is inflated and deployed like a curtain along a sidewall of a vehicle compartment so as to protect a head of an occupant. The gas-introducing path communicates only with predetermined inflation chambers.
In the head-protection airbag device according to the second and third aspects of the invention, upon side impact, rollover or the like of the vehicle, the gas is supplied from the gas supplier into the inflation chambers of the airbag, whereby the airbag is inflated and deployed like a curtain along the sidewall of the vehicle compartment. At this point, only the predetermined inflation chambers of the airbag can receive the gas from an early stage. Accordingly, the predetermined inflation chambers can be inflated and deployed quickly. This enables deployment of the airbag (curtain-like deployment) to be completed before a sufficient amount of gas flows into every inflation chamber of the airbag, allowing a reduction in the time for completion of deployment of the airbag.
In each of the aforementioned aspects of the invention, the predetermined inflation chambers may have a smaller volume than that of the remainder. Thus, the predetermined inflation chambers can be inflated and deployed with a smaller amount of gas, allowing a further reduction in the time for completion of deployment of the airbag.
In each of the aforementioned aspects of the invention, the predetermined inflation chambers may be disposed at locations away from the head of the seated occupant in a fore-and-aft direction of the vehicle. Accordingly, the airbag can be deployed with an inflation chamber at a location corresponding to the head of the seated occupant being insufficiently inflated. This enables the airbag to be accurately interposed between the sidewall of the vehicle compartment and the head of the seated occupant even if there is only a small space therebetween.